Abstract: Using the static water test method, acute toxicity test of five common used disinfectants on juvenile Cyprinus carpio with full length of (4.73±0.82) cm was carried out at water temperature 26~28℃. The safe concentrations of five kinds of disinfectants were as follows: chlorine dioxide (4.960 mg/L), potassium permanganate (0.773 mg/L), bromochlorine (0.290 mg/L), trichloroisocyanuric acid (0.057 mg/L), and polyvidone iodine (0.071 mg/L), respectively. The order of their toxicities was trichloroisocyanuric acid > polyvidone iodine > bromochlorine > potassium permanganate > chlorine dioxide.